In vitro germination and regeneration of Senna artemisioides, a valuable leguminous ornamental shrub

Abstract

Τhis research was carried out at the prospect of introducing new ornamental species in the floriculture industry concerning the use of valuable plants. A leguminous species native to Australia was the object of the present study.  Seeds of Senna artemisioides established in a private botanical garden were chosen as the starting material for both germination and in vitro studies. Hot water treatment at 90 °C, for 10 min was applied to interrupt the seed-coat dormancy. Incubation was conducted in vitro in Petri dishes, at seven different temperatures ranging from of 5.0 to 35.0 °C, involving three separate treatments of incubation at 5.0 °C, for 0, 30 and 60 days. The seeds germinated at 25 °C (56.0%). Node explants derived from produced seedlings were cultured in vitro onto Murashige and Skoog media (MS), hormone free (Hf) or containing 6-Benzyladenine (BA). The establishment of initial cultures was successful being higher on MS supplemented with BA at the range 0.1-1.0 mg L-1 media. The multiplication phase followed on MS media containing the same range of a total of four cytokinins widely used in in vitro experimentation, i.e BA, Kinetin (KIN), N6-Isopentenyladenine (2IP) and Zeatin (ZEA). 1-Naphthaleneacetic acid (NAA) was tested in conjunction with the higher concentration of the four cytokinins. MS media supplemented with BA at 0.5 mg L-1 led to a satisfactory proliferation rate; 2.4 shoots/explant were formed. Rooting phase had moderate efficiency, being higher for media with 4.0 mg L-1 IBA. Acclimatisation was successful for all rooted plantlets, promising an effective method for exploitation of this new ornamental species of high value.